Improvement in guard for door-knobs



`N f n ttn'itrd faire @anni (twice.

WILLIAM W. GUILD, OF WALPOLE, NEW HAMPSHIRE, ADMINISTRATOR OF THE ESTATE OF JAMES W. MELLISH, DEOEASED.

Letters Patent No. 91,116, dated June 8, 1869.

IMPROVEMENT IN GUARD FOR DOR-KNOBS.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it ma/y concern Be it known that JAMES W. MELLIsH, of Walpole Cheshire county, New Hampshire, did invent a new and useful Improvement in Door-Locks; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

The nature of this invention consists in the construction and general "arrangement of an inside fastening for door-locks, by means of which the lock is rendered perfectly burglar-proof.

In order to enable others skilled in the art to which this invention appertains, to make and use the same, I will now proceed to describe its construction and operation, referring to the annexed drawings, which form a part'of this specification, and in whicl Figure 1 is a longitudinal vertical section;

Figure 2 is a side and-edge-view of the outer plate of the'bnrglar-proof;

VFigure 3 shows the sliding gripe;

Figure 4 shows `the movable cam-plate; and Figure 5 1is an inside view of the burglar-proof complete.

A represents the door in which the lock is placed, O-is the knob-spindle, and D D, the knobs, about the construction of which there is nothing new, except that the knob-spindle G has a notch or recess, a, cut into it at a suitable point.

To the inside of the door A, the door-fastening is secured.

This fastening consists of an outer circular plate, E, which is fastened to the door by means of screws through the ear-pieces b b.

Through the centre of the plate E is a hole, c, through which the spindle or bar O passes.

d isa recess or depression in the under surface of the plate, made to receive the/sliding gripe F. This recess extends across the centre ofthe plate, as shown in iig. 2.

On each side of the recessd are lesser depressions, e e, upon which the cam-plate G rests.

The rim ff of the plate rises above these depressions, and rests on the door when the plate is fastened in position.

G represents the cam-plate, which moves the sliding gripe F, and' is constructed of circular shape, and of such size as to fit in the depressions e e, inside of the rirn f, on the plate E. I

The plate G is provided with a hole, g, through which the spindle C passes. It is also provided with a cam-shaped slot, h, running from near its centre to near its periphery, and made to receive the projecting pin, t, on the sliding gripe F, shown in iig. 3.

k is a projection from the edge/of the cam-plate, from one side of which extends a thumb-piece, l, by which the cam-plate is moved. A I

F represents the sliding gripe, through which the knob-spindle C passes.

Said gripe is made to fit inthe recess or depression,

d, of the circular plate E, and of such length that it may be moved backward and forward in said recess.

The gripe F is provided with a slot, m, of sufficient width to allow the gripe'to slide easily upon the knobspindle, and is made round 'at one end, to allow the spindle to turn, when the gripe is raised up,A for the purpose of unlocking the door.

'i is the pin, above mentioned, which enters into the cam-shaped slot, h, of the plate G, when the parts are in position.

The upper end of the slot mis cut diagonally across from one side of the slot to the other, and is so made that it may pass into the notch or recess, a, in the knob-spindle, when the door is fastened, to prevent the spindle being moved, should either of the knobs be detached.

To put the fastener together, put the sliding gripe F into the recess, d, of the circular plate E. Then put the cam-plate G over it, with its slot, h, upon the projecting pin, t', of the gripe. The projecting piece Ic, with its thumb-piece l, extends beyond the edge of the circular plate E, the rim f being suitably cut ont for that purpose'. The fastener is then secured to the inside of the door, as above described, so that the spindle passes through the holes made for that purpose.

When the sliding gripe F is moved, by turning the cam-plate G, so that the round portion of the slot fm is around the knob-spindle, then the lock can be opened; but, when the said gripe is moved down,`the spindle cannot be turned.

The advantages of this device are obvious, and I deem it not necessary to mention more than a few:

There is no key-hole, to allow the insertion of any key or instrument from the outside to pick the same.

It is easily operated.

It never locks or unlocks itself.

The knob-spindle cannot be reroved from the ontside, to allow of the introduction of any instrument to turn the catch, and unfasten the door, as the diagonal end of the slotm passes into the notch,-a, on the knobspindle, and prevents any lateral motion of the same.

Having thus fully described the invention,

What I claim as new, and desire to .secure by Letters Patent, is

l. Cutting a notch or recess in the knob-spindle, to receive a portion of the metal of the sliding gripe F, and to prevent any movement of the knob-spindle endwise, substantially as herein set forth.

2. In combination with a knob-spindle cut with a notch or recess, as described, the sliding gripe F, the movable cam-plate G, and the main plate E, all constructed and arranged to operate substantially in the manner and for the purposesl set forth.

-In testimony that I claim the foregoing, I have hereunto set my hand, this 1st day of March, 1869.

WILLIAM W. GUILD, Witnesses: .Adm/r.

JOHN W. LovnJor, EUGENE E. Plz-Esser. 

